Switching means



June 15,1948. c. l. l -lALL. 2,443,452

SWITCHING MEANS Filed Nov. 17, 1943 Inventor: 7 Chester 1. Hall,

Patented June 15, 1948 SWITCHING MEAN SJ Chester 1. Hall, Vischers Ferry,'.N..Y., assignor. to: General Electric Company, a corporation of? New York ApplicationNovember- 17, 1943-, Serial No. 510,613

3 Claims. 1

My invention relates to'switching means, more. particularly motor operated: switching means, and has for its object simple and reliable shock.- proof voltage responsive switching means for transfe-rringa'loadcircuit from a normal supply. circuit to an emergency supply circuit in the event of failure of the normal supply circuit;

In carrying out my invention, I control the operation-bfsupply source transfer switches by a relay-switching device which is operated in response to voltage by: means of a small electric motor connected' to the normal supply source. Under normal voltage conditions, this motor turns against a biasing spring to move the relay to-wpositionin which thenormal supply source is connected to'theload circuit. In the event of a decreasein the voltage of the normal supply circuit-:to apredetermined minimum value or theopening f"any one oithe three feeder lines due to damage, the torque of the motor is-overcome by'jthe biasing spring and the motor and relay switch' turned to another position in which the transfer-switches are reversed to connect the emergency, supply circuit to the load circuit.

For'a'more complete understanding of my invention; reference should be had to the accompanying'drawing in which Fig. 1 is an elevation view ofa control relay embodying my invention; Fig. Zis'a side elevation view of the device shown in Fig. 1; while Fig. 3 is a diagrammatic representation of-th'e relay of Figs. 1 and 2 connectecl' toOperatethe transfer switches.

R'eferringto the drawing, in one form of my inventlonIprovide a relay switch comprising'a' pivotedswitch member [0' mounted on a stationary'pivot H and provided with two movable contacts l2' and l3 which are electrically insulated from'each other. Preferably, as shown, the'reiay'is provided with a block M of electrically insulatingmaterial to opposite sides of which the movable contacts are secured, this bl'ochbeing pivotally mounted adjacent its upper side, as;viewed'in Figs. 1 and 2 on the pivot ll; Preferably}. as shown, themovable' contacts are mounted on the ends of spring arms which area'daptedto'fieX-to give a wiping action between theengaging contacts. Suitable terminal con nectors: I5," l.6, lTand l8 are provided on asupport" I=9"made' of electrically insulating material b'y'meansof which electric connections are made to: the movable contacts, and also to the stati'onary contacts and M, the stationary contacts being mounted on the insulating support-l9? Secured also to the block l lis ametal 'arm =22= 21', which extendsdownward; as seenin Figs: 1:- and 2, and-:has its lower. end bifurcatedito provide as. slot 231- having. a circular,v bottom. In; thissslote an operating? eccentric 24* moves in engagement" with opposite asideewall'ssof: the slot foria'ctuation'a of the block M'and' the'movable contactsabout the pivot; it into engagement with one" or.- theotherof'the stationary contacts.

For the actuation .oiiithe' eccentric: 24; a-voltage inc responsive actuating means isprovided'consiste ing, as-shown; of anelectric motor 25 ofasuitable two-phase type having. two windings 218 and 2'1:

connected as shown in Figs 3 to :two phases of then normal three-phase supply source. 28; As shown:

the motor: is provided with a'squirrel cage rotor 2-9 on the shaft 30 of which the eccentric Z4518. mounted. Ihe motor is furthermore. adapted-to. remain electrically connected to the supplyssourcez- 28' for an indefinite time after its rotorhas been brought to rest mechanically;

As shown, the slot 23 and the eccentric 24 arearranged' relative to each other so that the-cc centric has approximately 180" degrees freedom.

of movement; In its position shown in Fig. 1, the

eccentric is midwaybetween its two extreme posb tions and canbe movedsubstantially degrees"v in each direction from this central position-. Under normal operating conditions, it will be understood that the eccentric will'not remain-in. this'mid position-since it-will :be turned in one-- direction, such as clockwise,- by aspiral biaslng' spring 3| ninety degrees to one extreme position or it will'be turned in the opposite directionby the motor toits other extreme position. In each of these two extremepositions, the eccentric engages the circular bottom of the-slot" or the-recess 23" whereby it'is brought to rest.

It will be observed that, in each of these two extreme positions defined by 90 degrees rotation from-the position'shown in Fig. 1, the eccentric mm a locked or dead center position with respect to the sides of the slot 23'. In other words, in each of these'extreme positions, a force tending: to move the switch arm I0 about. its pivot is applied by one arm or the other of the slot to the eccentricin a direction to passthrough the axis of the shaft 39 and the eccentric. Thus the eccentric and the arm 22" form deadcenter crank operating means which looks the pivotedswitching device in each of these extreme positions-. This is an important feature of my invention and" assures-that the relay willnot be inadvertently operated by heavyshocks;

For the" purpose of absorbing the energy of the rotor- 29' and other moving parts; I provid'e a frictional driving connection between the shaft 30 and the eccentric. To this end the eccentric is mounted on a sleeve 32 which is slidably and rotatably mounted on the shaft 30. This sleeve is provided with two circular discs or flanges 33 and 34 on opposite sides of the eccentric and having their centers coincident with the axis of the shaft. As shown, the forked portion of the member 22 is positioned between these two circular members 33 and 34 which serve to maintain it in driving relation with the eccentric. Secured rigidly to the outer end of the shaft 30 is a disc 35 of the same size as the disc 33, and between these two discs is a friction disc 36 made of a suitable material, such as felt. A helical spring 31 surrounding the shaft 30 (Fig. 2) has its lefthand end bearing against the sleeve 32 and forcing the disc 33 against the friction disc 36. The other end of the spring bears against a suitable flange (not shown) on the shaft 30.

The spiral spring 3! has its inner end secured to the sleeve 32 while its outer end is secured to an adjustable bracket 38 adjustably secured by screws 39 to a support 40 to which is secured the support If! and also the electric motor 25.

In the operation of my invention, the relay I is connected to control the energization of two operating coils and 42 which operate switches 43 and 44 normally biased to their open positions controlling the connection of the normal threephase supply source 23 and an emergency supply source 45 to a load circuit 48. As shown in Fig. 3, the relay I0 is turned by the motor 25 against the biasing spring 3! to a position to energize the coil 42 and close the switch 44 with electric power applied to the circuits, while the coil 4! is deenergized for opening of the switch 43 in accordance with its bias.

When power is applied to the sources 28 and 45 by suitable switches (not shown) if the voltage of the source 28 is above a predetermined minimum value such as 80 per cent of its normal value, the torque exerted by the motor is sufficient to overcome the biasing force of the spring 3| and the motor therefore turns the eccentric 180 degrees in a counterclockwise direction, tothe position seen in Fig. 3, thereby to deenergize the coil 4| and energize the coil 42 for closure of the switch 44 and opening of the switch 43 in accordance with its bias. This connects the normal supply source 28 to the load circuit for normal operation.

In the event that for any reason the voltage of the normal supply source 28 fails or decreases to a value below the predetermined minimum voltage for which the relative torques of the motor and the biasing spring are adjusted, or in the event of failure of one phase resulting in loss of torque in the motor, the spring overcomes the force of the motor and turns the eccentric clockwise back to its biased position. This deenergizes the coil 42 for opening of the switch 44 and energizes the coil 4! for closure of the switch 43 thereby connecting the emergency supply source to the load circuit. Later on, in the event that the normal supply source voltage increases to a value above the predetermined minimum, the motor torque overcomes the bias of the spring and turns the relay to the position shown in Fig. 3, thereby automatically reconnecting the normal supply source to the load circuit.

While I have shown a particular embodiment of my invention, it will be understood, of course, that I do not wish to be limited thereto since many modifications may be made, and I therefore contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. A shockproof switch operating mechanism comprising a support, an operating member pivotally mounted at one end upon said support for movement between two angularly spaced switching positions, the other end of said operating member being bifurcated to provide an actuating slot having side walls joined by a bottom wall, an eccentric pivotally mounted for rotation between said side walls thereby to move said operating member between said switching positions upon rotation of said eccentric substantially degrees between two control positions, said eccentric being arranged to engage said bottom wall of said slot and be brought to rest thereby with said operating member in each of said switching positions and with said eccentric in a locked dead center position with respect to said side walls thereby to hold said operating member in each of said switching positions against the force of a shock applied to said support, electric driving means, and a slip clutch connecting said driving means to said eccentric providing for continued movement of said driving means after said eccentric is brought torest against said bottom wall when said driving means is operated to turn said eccentric from one control position to the other.

2. A shockproof switch operating mechanism comprising a support, an operating member pivotally mounted at one end on said support for movement between two angularly spaced switching positions, the other end of said switch operating mechanism being bifurcated to provide an actuating slot having side walls joined by a bottom wall, an eccentric pivotally mounted for rotation between said side walls of said slot, a torque motor, a slip clutch connecting said torque motor to turn said eccentric in one direction thereby to move said operating member to one switching position, said eccentric being arranged to engage said bottom wall of said slot and thereby be brought to rest with said operating member in said switching position and said eccentric in a locked dead center position with respect to said side walls of said slot thereby to hold said operating member in said position against the force of a shock applied to said support, and a spring connected to said eccentric to apply a rotational biasing force thereto in opposition to the force applied by said torque motor for turning said eccentric substantiall 180 degrees in the opposite direction until brought to rest by engagement with said bottom wall thereby to move said operating member to a second switching position when the torque of said motor is decreased to a predetermined minimum value.

3. A shockproof selector switch operating mechanism comprising a support, a, pivoted switch operating member mounted at one end on said support and bifurcated at its other end to provide an actuating slot having side walls extending lengthwise of said member and parallel with the pivot of said member joined by an arcuate bottom wall, an eccentric pivotally mounted for rotation between said side walls of said slot, electric driving means connected to turn said eccentric in one direction thereby to move said operating member on its pivot to one switching position, said eccentric being arranged to engage said bottom wall of said slot and thereby be brought to rest and stall said driving means with said operating member in said switching position and said eccentric in a locked dead center position with respect to said side walls of said slot thereby to hold said operating member in said position against the force of a shock applied to said support, a frictional driving connection between said driving means and said eccentric, and a spring connected to said eccentric to apply a rotational biasing force thereto in opposition to the force applied by said driving means for turning said eccentric substantially 180 degrees in the opposite direction until brought to rest by engagement with said bottom Wall thereby to move said operating member to its other switching position when the torque of said driving means is decreased to a predetermined minimum value.

CHESTER I. HALL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 454,983 Mills June 30, 1891 1,284,937 Simon Nov. 12, 1918 1,385,146 Meyers July 19, 1921 1,435,255 Puxon Nov. 14, 1922 1,609,292 Burch Dec. 7, 1926 1,781,561 Walle Nov. 11, 1930 2,170,982 Ellenwood Aug. 29, 1939 2,319,000 Jones May 11, 1943 

